Yaskawa G7 Drive - Manual (Page 301)

6
-84
Individual Functions
This section explains the individual functions used in special applications.
‹ Using MODBUS Communications
You can perform serial communications with MEMOCON-series Programmable Controllers (PLCs) or simi-
lar devices using the MODBUS protocol.
„ MODBUS Communications Configuration
MODBUS communications are configured using 1 master (PLC) and a maximum of 31 slaves. Serial commu-
nications between master and slave are normally started by the master, and the slave responds.
The master performs signal communications with one slave at a time. Consequently, you must set the address
of each slave beforehand, so the master can perform signal communications using that address. Slaves receiv-
ing commands from the master perform the specified function, and send a response to the master.
Fig 6.54 Example of Connections between PLC and Drive
„ Communications Specifications
The MODBUS communications specifications are shown in the following table.
Item Specifications
Interface RS-422, RS-485
Communications Cycle Asynchronous (Start-stop synchronization)
Communications Parameters
Baud rate: Select from 1,200, 2,400, 4,800, 9,600, and 19,200 bps.
Data length: 8 bits fixed
Parity: Select from even, odd, or none.
Stop bits: 1 bit fixed
Communications Protocol MODBUS (RTU mode only)
Number of Connectable Units 31 units max. (when using RS-485)
MEMOCON-series PLC
RS-485 connections
example
Drive Drive Drive